#pragma once
template<class T> class Luna {
  public:
    static void Register(lua_State *L) {
      lua_pushcfunction(L, &Luna<T>::constructor);
      lua_setglobal(L, T::className);

      luaL_newmetatable(L, T::className);
      lua_pushstring(L, "__gc");
      lua_pushcfunction(L, &Luna<T>::gc_obj);
      lua_settable(L, -3);
    }

    static int constructor(lua_State *L) {
      T* obj = new T(L);

      lua_newtable(L);
      lua_pushnumber(L, 0);
      T** a = (T**)lua_newuserdata(L, sizeof(T*));
      *a = obj;
      luaL_getmetatable(L, T::className);
      lua_setmetatable(L, -2);
      lua_settable(L, -3); // table[0] = obj;

      for (int i = 0; T::Register[i].name; i++) {
        lua_pushstring(L, T::Register[i].name);
        lua_pushnumber(L, i);
        lua_pushcclosure(L, &Luna<T>::thunk, 1);
        lua_settable(L, -3);
      }
      return 1;
    }

    static int thunk(lua_State *L) {
      int i = (int)lua_tonumber(L, lua_upvalueindex(1));
      lua_pushnumber(L, 0);
      lua_gettable(L, 1);

      T** obj = static_cast<T**>(luaL_checkudata(L, -1, T::className));
      lua_remove(L, -1);
      return ((*obj)->*(T::Register[i].mfunc))(L);
    }

    static int gc_obj(lua_State *L) {
      T** obj = static_cast<T**>(luaL_checkudata(L, -1, T::className));
      delete (*obj);
      return 0;
    }

    struct RegType {
      const char *name;
      int(T::*mfunc)(lua_State*);
    };
};